Lepidoptera Trail Virtual Tour

This interpretive trail provides food for butterflies, moths and skippers (collectively known as Lepidoptera) during both the caterpillar and adult stages.

Most adult Lepidoptera are generalists that drink nectar from a variety of flowers, but many caterpillars can survive only by feeding on specific types of plants. As development continues to threaten local biodiversity, this trail provides the plants necessary to support 23 species of caterpillars, an essential part of the food web.

Welcome to the Lepidoptera Trail!

The Lepidoptera Trail in the Native Garden supports Lepidoptera―the order of insects that includes butterflies, moths, and skippers. It features stops at specific host plants that attract specific species of caterpillars (Lepidoptera larvae), with nearby interpretive signage offering images and information about the targeted species.

Travel the virtual Lepidoptera Trail to discover the featured plants and insects and learn about their essential relationships. Move your mouse over the images for more information, and click "next" to move forward.

Food for Larvae and Adults

Caterpillar host plants are not the only plants you’ll see while walking the Lepidoptera Trail. A variety of nectar flowers serve newly metamorphosed flutterers, and attract other nearby adult Lepidoptera to lay their eggs on adjacent host plants.

Baptisia hosts eastern tailed blue caterpillars. Its flowers also provide nectar for a variety of butterflies.

Targeting Our "Audience"

Butterfly adults are generalists that drink nectar from a variety of flowers, but caterpillars are often picky specialists that survive only by eating certain plants. The Lepidoptera Trail includes a balanced mixture of plants for both larval and adult Lepidoptera.

Spicebush hosts spicebush swallowtail caterpillars. The early-flowering shrub is common in local woodlands.

Food vs. Food Eater

Caterpillars eat plants, and plants need protection from being eaten. Both are engaged in an evolutionary arms race—plants produce chemicals that protect them from herbivores, and caterpillars must overcome these chemicals to be able to eat the plant.

Violet hosts variegated fritillary caterpillars, which have adapted to toxins in violet leaves. Non-adapted insects would likely become sick from the plant’s chemical defenses.

The Science of Specialization

Every lineage of plant produces a specific type of toxin. No caterpillar can adapt to all toxins, so caterpillars specialize on overcoming the specific toxins produced by a specific lineage of plants. Thus, caterpillars can only survive on host plants to which they are adapted.

Golden Alexander hosts black swallowtail caterpillars. This species of caterpillar requires plants in the carrot family for survival.

Enticing the Ephemeral Moths

Many moths lack mouthparts and don’t feed at all after becoming adults. They simply mate, lay eggs, and die. Because they aren’t drawn in by nectar plants, caterpillar host plants are essential for attracting them to the Native Garden.

Sweetgum hosts luna moth caterpillars. Like many members of the giant silk moth family, only the young require plants for food.

Under the Cover of Night

Moths, unlike butterflies, are generally nocturnal. Although many moths lack the mouthparts to feed, they venture out at night to mate and lay eggs. Many nocturnal moths provide an important food source for bats, which are another crucial link in the food chain.

Chestnut oak hosts rosy maple moths. Primarily nocturnal, rosy maple moths emerge in late afternoon to mate in the evening. To view these beautiful moths, hang a white sheet and project a light onto it after dusk.

Generalist Caterpillars...

Redtwig dogwood isn’t anything special for the cecropia moth caterpillar. It is well-adapted to eating plants from several different families. Still, this generalist can’t escape its evolutionary history. Click along to the next stop to find out why.

Redosier dogwood hosts cecropia moth caterpillars. You can also search for the colorful caterpillar on black cherry, sassafras, gray birch, and other native dogwoods.

...Are Still Native Specialists

Adapting to toxins can require tens of thousands of years, so even generalists can only eat their local plants. UD researchers placed eggs of the white marked tussock moth, a generalist, on plants from Asia. The caterpillars died soon after hatching, poisoned by unfamiliar chemical defenses.

Red maple hosts white-marked tussock moth caterpillars. Though one of the top generalists in terms of plant species it can eat, the caterpillar is still limited to native plants with which it evolved.

Taking Advantage of Toxins

Many caterpillars don’t just adapt to plant poisons—they adopt them. By absorbing toxins into their body tissues, caterpillars can become poisonous themselves, a defense against predators that lasts into adulthood.

Swamp milkweed hosts monarch caterpillars. By incorporating poisonous milkweed sap into their own bodies, monarchs become poisonous to predators both as caterpillars and adults.

Taking Advantage of Toxins, Part II

Like the monarch butterfly, the pipevine swallowtail butterfly is unpalatable to predators because of the pipevine plant it consumes. Birds recall the undesirable taste of the pipevine swallowtail and associate it with their black coloration, thereby refusing to eat all similar black butterflies.

Fallen Leaves Provide Shelter

Similar to many Lepidoptera, sphinx moths such as the snowberry clearwing overwinter in fallen leaves. In the Lepidoptera Trail, we retain some of our autumn leaves as leaf mulch to provide a winter home to moth cocoons.

Camouflage as Protection

The camouflaged looper (also known as wavy lined emerald moth) can appear virtually invisible to predators by its unique camouflaged defense. It snips off pieces of plants it feeds on to attach to its body. This unusual method of disguise helps the caterpillars look like part of a plant to a passing predator.

Paper birch hosts camouflaged looper caterpillars. These caterpillars are often found munching on plants in the aster family, although they also feed on a range of woody plants.

Non-Truths in Advertising

The monarch butterfly wears bright colors to warn predators of their poisonous nature. To make it easy for predators to remember, the viceroy butterfly uses the same color pattern to warn predators that they taste bad. The viceroy’s caterpillar, however, employs an entirely different disguise!

Silky willow hosts viceroy caterpillars. Both live in wet, open areas, and the caterpillar fools predators by imitating bird-droppings. Butterflies imitate the warning coloration of monarch butterflies.

Bird Food

Despite their incorporated toxins and clever disguises, caterpillars are one of the best food sources for birds. Over 96% of our local birds rear their young on insects, and caterpillars serve as a high-protein, high-energy source.

Virginia creeper hosts pandorus sphinx moth caterpillars. The caterpillar may be dark red, orange, pink, or green during different stages of growth--keeping bird mothers on their toes as they seek food for their young.

Jumpstarting the Food Web

Birds are only one of the many animals that depend on insects for food. Insects have an essential role in transferring energy from plants to non-plant eating animals, either directly or indirectly. By planting for caterpillars, the Lepidoptera Trail sustains food webs and helps preserve local ecosystems.

Indigobush amorpha hosts the silver spotted skipper caterpillar. The caterpillars get energy from eating indigobush amorpha and other legumes; other wildlife receive energy by gobbling up the caterpillars.

All Plants are Not Created Equal

…According to insects! When it comes to feeding a variety of caterpillar species, some plants are better than others. Oaks are the top trees for caterpillar fodder, supporting 534 different species in our area.

Oak hosts polyphemus moth caterpillars. Planting oaks is one of the best ways to support insect and insect-predator biodiversity. Though slow-growing in comparison to other trees, even small specimens--“oak bushes”--can support a large number of Lepidoptera in the landscape.

Superior Food Sources, Part II

Black cherry is another caterpillar powerhouse, feeding 456 different species. Locally, it is a favored host for the red-spotted purple, io moth, and white furcula caterpillars, among others.

Black cherry hosts red-spotted purple caterpillar. Search among the leaves of this tree and you may discover any number of interesting caterpillar species.

Flower Shape is Important

Many adult Lepidoptera can only partake of nectar from flowers in the correct shape. The sphinx moth prefers trumpet- or tube-shaped flowers (such as honeysuckle). It uses its long, straw-like mouth structure to get the hard-to-reach nectar from these flowers.

Why Garden for Caterpillars?

Why do we need to invite caterpillars to munch leaves in our garden? Can’t they just live on natural lands? The answer is a resounding “no” – there isn’t enough natural land left to support needed levels of biodiversity.

Possumhaw viburnum hosts hummingbird clearwing moth caterpillar. Viburnums are common in Delaware woodlands; unfortunately, Delaware woodlands are becoming less and less common. In 2002, they were counted at only 23% of their original area.

Shrinking Natural Habitats

Long-term ecological studies show that the percentage of natural lands lost to development and agriculture equals the percentage of biodiversity that will become extinct over time. For example, if only 10% of natural areas remain, only 10% of species can continue to survive.

Nutmeg hickory hosts the hickory horned devil caterpillar (a.k.a. royal walnut moth). Hickories, black walnuts, sweetgums, persimmons, sumacs and its other host plants are continually threatened by development of forested land. Light pollution from developed areas has also taken a heavy toll on the royal walnut moth. Large moths like these endanger themselves to predators and exhaustion by their endless circling of nighttime light sources.

The Future of Biodiversity

Here in the United States, we currently devote 41% of our land to agriculture and 54% to cities, suburbs and roads, leaving only 5% of the land in undisturbed natural areas. Unless we change our gardening practices in our managed ecosystems, 95% of our biodiversity may disappearing in the coming years.

Black cherry hosts the io moth caterpillar, whose poisonous spines say “hands off, please!” Though now common on a range of native pants, this caterpillar’s delicate beauty could be lost forever.

Suburbia: The Last Frontier

Together, we can change this path of mass extinction! Currently, our suburban landscapes are planted largely with non-indigenous plant species that cannot support most of our local insects, the basis of the food web. We can improve our landscapes’ ability to support biodiversity by adding a variety of native plants.

Planting for the Future

Start small in your own garden to make a big difference for local wildlife. Devote some of your lawn space to native plants to create a more balanced ecosystem. A variety of native plants species will support a variety of local insects, which in turn support the entire food web. Our collective efforts can form biological corridors to help preserve local biodiversity.